How to add multiple checkboxlist items to SQL column

<td class="auto-style15">

                        <asp:CheckBoxList ID="AppList" runat="server" Height="60px" RepeatColumns="3" RepeatDirection="Horizontal" Width="486px">
                           <asp:ListItem>Business Central</asp:ListItem>
                           <asp:ListItem>WineMS</asp:ListItem>
                           <asp:ListItem>CPAR</asp:ListItem>
                           <asp:ListItem>OperaPMS</asp:ListItem>
                           <asp:ListItem>My Micos</asp:ListItem>
                           <asp:ListItem>Micros EMC</asp:ListItem>
                           <asp:ListItem>Jet Professional</asp:ListItem>
                           </asp:CheckBoxList>

                   </td>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Data;
using System.Configuration;




namespace EmployeeRequest 
{
    public partial class EmployeeRequestForm : System.Web.UI.Page
    {

        string ConnectionString = @"Data Source=sh-jasonkNew\ICTDev;Initial Catalog=NewUserReqForm;Integrated Security=True;";
     

        protected void Page_Load(object sender, EventArgs e)
        {
           
        }
      
        protected void btnSubmit_Click(object sender, EventArgs e)
        {

            if (txtName.Text == "" || txtSurname.Text == "" || txtDepartment.Text == "")
                lblErrorMessage.Text = "Please fill Mandatory Fields";
            using (SqlConnection sqlCon = new SqlConnection(ConnectionString))
            {

                sqlCon.Open();
                
                SqlCommand SqlCmd = new SqlCommand("EmployeeAdd", sqlCon);
                SqlCmd.CommandType = CommandType.StoredProcedure;
                SqlCmd.Parameters.AddWithValue("@Name", txtName.Text.Trim());
                SqlCmd.Parameters.AddWithValue("@Surname", txtSurname.Text.Trim());
                SqlCmd.Parameters.AddWithValue("@Department", txtDepartment.Text.Trim());
                SqlCmd.Parameters.AddWithValue("@EmploymentType", ddlEmploymentType.Text.Trim());
                SqlCmd.Parameters.AddWithValue("@CommenceDate", DateTime.Now);
                SqlCmd.Parameters.AddWithValue("@JobTitle", txtJobTitle.Text.Trim());
                SqlCmd.Parameters.AddWithValue("@TelephoneExt", txtTelephoneExt.Text.Trim());
                SqlCmd.Parameters.AddWithValue("@Gender", ddlGender.Text.Trim());
                SqlCmd.Parameters.AddWithValue("@Workstations", ddlWorkstations.Text.Trim());
                SqlCmd.Parameters.AddWithValue("@Applications", AppList.Text.Trim());
                SqlCmd.Parameters.AddWithValue("@FolderAccessRights", txtFolderAccessRights.Text.Trim());
                SqlCmd.Parameters.AddWithValue("@EmailGroupAccess", txtEmailGroupRights.Text.Trim());
                SqlCmd.Parameters.AddWithValue("@Authorisedby", txtAuth.Text.Trim());
                SqlCmd.ExecuteNonQuery();
                Clear();
                lblSuccessMessage.Text = "Information Submitted Successfully";



            }
        }

        void Clear()
        {
            txtName.Text = txtSurname.Text = txtDepartment.Text = Cal1.Text = ddlEmploymentType.Text = txtJobTitle.Text = txtTelephoneExt.Text = ddlGender.Text = txtFolderAccessRights.Text = txtEmailGroupRights.Text = txtAuth.Text ="";
            hfEmployeeID.Value = "";
            lblSuccessMessage.Text = lblErrorMessage.Text = "";

        }

        protected void Calendar1_SelectionChanged(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {

            }
        }
        protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
        
        {
            string chkboxselect = "";
            for (int i=0;i<AppList.Items.Count;i++)
            {
                if(AppList.Items[i].Selected)
                {
                    if(chkboxselect == "")
                    {
                        chkboxselect = AppList.Items[i].Text;
                    }
                    else
                    {
                        chkboxselect += "," + AppList.Items[i].Text;
                    }
                }
            }
            string mainconn = ConfigurationManager.ConnectionStrings["NewUserReqFormConnectionString1"].ConnectionString;
            SqlCommand sqlconn = new SqlCommand(mainconn);
            string sqlquery = "insert into [dbo].[tbl_EmployeeAdd] ([Applications]) values ('"+ chkboxselect + "')";
           
            
        }
            

        protected void Calendar1_DayRender(object sender, DayRenderEventArgs e)
        {
       
           
        }


        
    }
}

string chkboxselect = "";
           for (int i=0;i<AppList.Items.Count;i++)
           {
               if(AppList.Items[i].Selected)
               {
                   if(chkboxselect == "")
                   {
                       chkboxselect = AppList.Items[i].Text;
                   }
                   else
                   {
                       chkboxselect += "," + AppList.Items[i].Text;
                   }
               }
           }
           string mainconn = ConfigurationManager.ConnectionStrings["NewUserReqFormConnectionString1"].ConnectionString;
           SqlCommand sqlconn = new SqlCommand(mainconn);
           string sqlquery = "insert into [dbo].[tbl_EmployeeAdd] ([Applications]) values ('"+ chkboxselect + "')";


       }